I have a 2006 Ram 3500 4WHD automatic with around 130,000 miles on it so far, I stopped earlier this year in January at one of the local chain oil changing places, they replace the Wix stock replacement air filter with their house brand that has a foam bottom on the inlet side of the element. I keep track of every fuel fill up and check the fuel mileage based on the trucks speedometer, it has got between 12.5 and 14.5 MPG around town before the air filter change. It went up to over 18.+ MPG with the new filter but I didn't think anything about it until I noticed the dirty air filter indicator on the stock air box showing it was dirty after two tanks of fuel so I reset it and it did the same thing in two more fill ups, around 2000 miles total on that element. I replaced that air filter with another stock Wix replacement type element and the mileage is now back to 12.8 to 14.5 around town after three tanks of the same fuel brand
All comments, inputs and your thoughts on this will be appreciated, Thanks